He attained geek immortality by co­inventing the Sol-20 personal computer in the mid-1970s. He was a key member of the legendary Homebrew Computer Club and a recurring character in Steven Levy's 1984 book, Hackers. So you'd think that nowadays Bob Marsh might be tripping the light fantastic like fellow personal-computer pioneer Steve Wozniak, or at least kicking back and enjoying retirement.

But Marsh, 63, doesn't kick back. Fueled by coffee (really good coffee) and surrounded by a cadre of earnest young engineers, he's hard at work bridging the digital divide. By any means necessary.

"What's one of the key differences between someone in a village in Africa and someone here in the United States, even a poor person in a poor community?" he asks. Answer: "Google. If you have Internet access and Google, you can find anything."

As one of three cofounders of the San Francisco–based nonprofit Inveneo, and with funding from partners like Advanced Micro Devices, Cisco, and the United Nations, Marsh trots the globe to establish new computer centers in some of the world's most isolated and undeveloped locales. In partnership with local organizations, he's worked lately in Kenya, Mali, Rwanda, and Bangladesh.

"If you're in a capital city in any third-world country, say, Kinshasa or Kabul, you have all kinds of technology available," says Marsh. "But it's pretty hard to get access to technology at some little village in the middle of the jungle."

On a sunny October day in San Francisco, Marsh is brainstorming with coworkers at Inveneo's loftlike office at the edge of the city's downtown district. He'll be gone for the next four weeks, and he'll schlep from one side of the Democratic Republic of Congo to the other, starting in Kinshasa and ending in Bukavu, near the border with Rwanda.

The team has laid out Marsh's tasks and talked about what he should take with him. He doesn't travel light. As part of his job setting up installations, Marsh often carries with him 30-kilogram Pelican cases crammed with compact servers, disk drives, monitors, cables, and circuit breakers.

Marsh's work with Inveneo fits perfectly with the hacker ethic espoused at Homebrew meetings: Don't just spur innovation—use it to make people's lives better. For example, sensing a business opportunity in the wild and woolly early days of personal computers, in 1975 Marsh started a company called Processor Technology Corp., which made 4-kilobyte memory boards for the primordial Altair. Later that same year, he collaborated with Lee Felsenstein to create the Sol-20, now enshrined at the Smithsonian Institution.

Processor Technology became part of Silicon Valley lore, but it didn't exactly mint money for Marsh. For the next 20 years, he went from start-up to start-up, with a brief detour into California state politics on behalf of the Green Party. Then, in 2001, while Marsh was working as director of hardware development at a medium-size wireless-equipment manufacturer, the dot-com bubble burst, and he was out of a job.

At that point, his old hacker pal Felsenstein brought him into the Jhai Foundation, which was bringing bicycle-powered computers and Internet access to a small village in Laos [see "It Takes a Village," IEEE Spectrum, September 2003]. But within a year he'd soured on Jhai—he won't say exactly why—and decided to strike out on his own. In 2002, he founded Inveneo with former Jhai volunteers Kristin Peterson and Mark Summer.

"Silicon Valley is a real rat race, and it can get to you," Marsh says. "By the time I got to my late 50s, I was thinking, can I do this whole start-up thing, working 16-hour days six or seven days a week? Again?" He laughs. "I wanted to do this kind of work. Time to give back, you know, what I've learned." It also helped that he had some measure of financial security after receiving a modest inheritance from his mother, so he was able to go without a paycheck at Inveneo for the first two years.

His first creation was the low-power Inveneo Computing Station, assembled from off-the-shelf parts. Optimized for operation in tropical conditions, the computer and display consume about 17 watts total. They can run on either 100/240-volt AC or 12-V DC, allowing them to be used with wall current, solar panels, or 12-V batteries. The station can run either Ubuntu Linux or Microsoft Windows XP.

So far, Inveneo and its local partners have installed these and similar systems in more than 300 communities in 23 countries. Now you can add the good people of Bukavu to the list. Marsh spent three weeks toiling in the drenching downpours of eastern Congo, because, as he put it in an e-mail, "Failure Is Not An Option! I returned to the hotel tonight about 10:15pm after an exhausting but fulfilling day... IT'S ALL WORKING!!!" And those are about the sweetest words a real hacker could utter.